We coin 'neo-scepticism' as a term to describe an emerging science-policy argument that opposes major efforts to mitigate climate change. Neo-sceptics do not deny anthropogenic global warming, but minimize its projected effects and see mitigation efforts as unjustifiable (see, for example, S. E. Koonin Wall Street Journal 19 September 2014; J. Curry Wall Street Journal 9 October 2014).

Neo-sceptic arguments emphasize well-known uncertainties in climate science, particularly over predicted temperature changes. This diverts attention from the risks of events with extreme biological and economic consequences and from the risks of 'tipping points' with large, nonlinear responses.

Neo-sceptics recognize the importance of policy decisions — who should do what, when, and at what cost, for example. However, they project an ironic certainty in advising the postponement of serious mitigation efforts until confidence intervals for climate projections are narrowed.

Physicists, biologists and social scientists should be focusing more on risks, rather than simply pursuing more-precise estimates of physical parameters that are not linearly related to the most worrisome hazards. Society does not demand certainty to cope with other high-consequence risks, such as those relating to public health, airline safety, terrorism, and natural or technological disasters.